Thermostat



y Q A. A. WARNER 1,910,510

THERMOSTAT Filed April 14, 1931 p I 1. 3E. 55 76 25 22 ATTORNEYS Patented May 23, 1933 spring constantly urging it to the UNITED STATES PATENT OFFICE ALONZO WARNER, OF NEW BRITAIN, CONNECTICUL ASSIGNOR TO LANDmS, FRAIRY a CLARK, 01' NEW BRITAIN, CONNECTICUT, A CORPORATION OF CONNECTICUT TEERMOSTAT Application filed April 14,

The present invention relates to thermostats and especially to a temperature control switch having a positive snap action to on and 011' positions.

' The principal object of the invention'is to provide a temperature control switch having a movable contactor under the control pf :11

on position and, under certain temperature conditions, maintaining the movable contactor in oil? position.

1 Other objects and advantages of the invention will appear from the following description taken in connection with the accompanying drawing which illustrates, by way of example, a preferred embodiment of the invention and in which Figure l-is a fragmentary side elevation, partly broken away, illustrating a preferred form of the invention;

Figure 2 is a vertical longitudinal sectional view through the thermostat of Fig. 1, on a slightly enlarged scale, taken on the line 2-2 of Fig. 4;

Figure 3 is a similar sectional view taken on the line 33 of Fig. 4;

Figure 4 is a bottom plan view;

Figure 5 is a vertical transverse section taken on, the line'55 of Fig. 2;

Figure 6 is a horizontal sectional view taken on the line 6-6 of Fig. 5; and

Figure 7 is a vertical transverse sectional View on the line 7-7 of Fig. 2.

Fig. 3.

a At the end of the base plate opposite to the seat 14 there is located an angleplate 22 Whose horizontal portion is secured to the base plate by rivets 24, or otherwise. To the inner face of the angle plate is secured, by rivets- 26 or otherwise, an insulator strip 28 in which are mounted a pair of terminals 30,

1981. Serial No. 529,943.

32, each in contact with a fixed contactor strip 34 extending vertically, as shown in Figs. 3 and 7. v

Fixed on the horizontal arm of the angle plate 22 is a bracket 36 having vertically extending parallel arms 38 provided with aligned openings 40 for the reception of the oppositely extending spindles 42 of a movable contactor 44 provided with an insulated conductor 46 adapted to bridge the fixed contactor strips 34, as in the position of Figs. 2 and 6, for closing the circuit, and to occu y the position of Fig. 3 upon opening of t e circuit. The arms 38 of the bracket are preferably provided with inwardly extending substantially horizontal rests 48 to support the weight of the rocking contactor 44,

bent portion serving to carry 'a revolubly mounted roller 54 adapted to be contacted, as illustrated in Fig. 3, by the bi-metallic leaf spring 18 upon increase of temperature. The base 12 is provided with a struck-up tongue or flange 56 which limits bodily movement of the roller 54, and consequently of the actuator 50, in one direction. The actuator is provided near its heel 52 with one or more slots or openings through which extend a corresponding number of projections 58 formed on the bottom of the bracket 36, bodily movement of the actuator 50 being thereby limited toward the right, as viewed in Figs. 2 and 3, the extensions 58 also cooperating with the flange 56 to vmaintain the actuator, at all times, in assembled operative position.

The invention provides a resilient connection between the actuator and the movable contactor, in this instance having the form of a U-shaped spring clip 60, whose bent ends tend constantly to move toward each other, one of the ends being hooked into the movable contactor 44 (see Figs. 3 and 5) and the other end being in engagement with the actuator.

under tension by the two members to which the clip is attached.

In operation, amuming the parts to be in the position of Fig. 2 with current flowing through the heating resistance in housing 64, with a socket over a pair of pin contacts, one

for conductor 66 and one for conductor 68, the currentwill flow through the conductor 68 into one of the fixed contact strips 34, across the bridge of the movable contactor 44, thence through the other contact stri 34, then through the conductor 70, the resistance, and conductor, 66. When, due to the heating resistance the temperature of the bi-metallic leaf spring-increases sufliciently and it bears upon the roller-54, as illustrated in Fig. 3, the roller will be urged toward the base 12, and, due to the spring 60, the actuator will rock on its heel 52 with a snap action from the position of Fig. 2 to the position of Fig. 3.

' In case the'contacts 46 and '34 stick or weld together, a finger 74'on the actuator will bear against a (prqection 76 on the movable contactor an force the contactors 46 and 34 apart, so that spring 60 can effect the snap rockin movement of the movable contactor about its axis. It will be observed that at the start of this movement, both engaged ends of the spring clip 60 are on the same side of a vertical plane containing the rocking axis of the movable contactor. As the movable contactor is forced to the position of Fig. 3, it will be evident from the drawing that the ends of the spring are forced further apart until both ends of the spring clip lie on the other side of said vertical lane. The moment these ends pass throng said plane the tension of the spring clip causes its ends to draw nearer together and hold the parts in the position of Fig. 3, in which the bridging contact 46 has opened the heating circuit. The parts are so proportioned and arranged that finger 74 will not engage projection 76 on the movable contactor when the parts are working freely, the spring 60 normally functioning in time to prevent this engagement. With the construction described, there is provided a spring-governed snap action in opening the circuit. With the heating resistance out of circuit and the bi-metallic leaf spring 18 cooling, its free end will move away from the roller gradually and the parts will begin to move gradually to the position of Fig. 2. Although the movement of the actuator 50 may be. very gradual, the moment the enged portions of the spring clip pass through the vertical plane of the movable contact axis, the arms of the spring clip move toward each other under their own tension and sna the movable contactor to the position of ig. 2, or closed circuit position, thus again bringing the heating resistance into action.

The invention provides means for varying the time of the operating intervals of the thermostat, and for this purpose, in the form shown, fingers 78 are provided on the actuator 50. The time intervals may be shortened ways on the same side of a vertical plane, in-

cluding the line of the heel 52, the effect of the spring clip is always to tend to move the actuator to the position of Fig. 2.

What is claimed is:

1. A thermostat including a pair of stationary contacts, a yicldable operating element, an actuator movable thereby to open and closed circuit positions, a movable contactor, and a spring cooperating with said actuator and said contactor, said'spring constantly urging said actuator toward circuit closing position and also urging said contactor toward said contacts in closed circuit position of said actuator and away from said contacts in open circuit position of said actuator.

2. A thermostat including a pair of stationary. contacts, a temperature responsive element, a rocking actuator movable thereby to open and closed circuit positions, a movable contactor, and a spring cooperating with said actuator and said contactor, said s ring constantly urging said actuator towar circuit closing position and also urging said contactor toward said contacts in closed circuit position of said actuator and away from said contacts in open circuit position of said actuator. I

3. A thermostat including a pair of stationary contacts, a temperature responsive element, an actuator movable thereby, a movable contactor, and a spring clip having a pair of arms constantly urged toward each other, one engaging said actuator and the other said contactor, said spring constantly urging said actuator toward circuit closing position and also urging said contactor toward said contacts in closed circuit position of said actuator and away from said contacts in open circuit position of said actuator.

4. A thermostat including a pair of stationary contacts, a temperature responsive element, an actuator rockable thereby about an axis, a contractor rockable about a substantially parallel axis, and a spring clip having a pair of arms one engaging said contactor between said axes and the other engag- Ian tially parallel axis, and a spring clip having a pair of arms one engaging said contactor between said axes on one side of said contactor axis and the other engaging said actuator on 5 the other side of said contactor axis.

6. A thermostat including a pair of stationary contacts, a tem )erature responsive element, an actuator roclmble thereby about an axis, a contactor rockable about a substantially parallel axis and having a portion between said axes engageable by said actuator, and a spring clip having a pair of arms one engaging said contactor between said axes and the other engaging said actuator.

7. A thermostat including a pair of stationary contacts, a temperature responsive element, an actuator rockable thereby about an axis, abracket having substantially parallel arms, a contactor pivotallymounted therein to rock about a substantially parallel axis, and a spring clip having a pair of arms one engaging said contactor between said axes and the other engaging said actuator.

8. A thermostat including a pair of stationary contacts, a temperature responsive element, an actuator rockable thereby about an axis, a bracket having a pair of substantially parallel arms provided with contactor rests, a contactor carried by said rests and tactor between said axes and the otherengaging said actuator.

9. A thermostat including a pair of stationary contacts. a temperature responsive element, an actuator movable thereb to open and closed circuit positions, a movable contactor, and a spring cooperating with said actuator and said contactor, said spring con stantly urging said actuator toward circuit closing position and also urging said contactor toward said contacts in closed circuit position of said actuator and away from said contacts inopen circuitposition of said actuator, said actuator having a portion engageable with said movable contactor during movement of said actuator to open circuit position at substantially the moment when the direction in which said spring urges said movable contactor is about to change.

10. A thermostat including a pair of stationary contacts, a yieldable operating element, an actuator movable thereby to open and closed circuit positions, a movable contactor, a spring cooperating with said actuator and said contactor, said spring constantly urging said actuator toward circuit closing position and also urging said contactor toward said contacts in closed circuit position of said actuator and away from said contacts in open circuit position of said actuator, and means for varying the operating intervalsof said thermostat;

11. A thermostat including a pair of stamy hand.

ALONZO A. WARNER.

pivoted loosely in said arms to rock about a substantlallv arallel axis, and as llIi ch J 1 hav ng a palr of arms one engaging said con- 

